Other teams with cap space -- Cavs, Nuggets, Pistons, Warriors, Rockets, Pacers, Bucks, Knicks, Thunder, Kings, Raptors, Wizards.
There is a lack of quality suitors next off-season. Most of those teams are lottery squads or borderline playoff teams. A lot of underwhelming cities + small markets.
The Rockets and Knicks would give the Nets a run for their money but outside of them ... the Nets offer would be the most attractive and they'd have the added bonus of having Carmelo on the team for half a year allowing them to convince him that NJ/Brooklyn is the best place for him to be.
I think the Nets would have a good chance of convincing Carmelo to stay.